In the field of computer networking and other packet-switched telecommunication networks, the term Quality of Service (QoS) is the ability to provide different priority to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow. For example, a required bit rate, delay, jitter, packet dropping probability and/or bit error rate may be guaranteed. QoS guarantees are important if the network capacity is insufficient, especially for real-time streaming multimedia applications such as voice over IP, online games and IP-TV, since these often require fixed bit rate and are delay sensitive, and in networks where the capacity is a limited resource, for example in cellular data communication.
A network or protocol that supports QoS may agree on a traffic contract with the application software and reserve capacity in the network nodes, for example during a session establishment phase. During the session it may monitor the achieved level of performance, for example the data rate and delay, and dynamically control scheduling priorities in the network nodes. It may release the reserved capacity during a tear down phase.
The Wireless Local Area Network (LAN) split-plane architecture involves creation of tunnels between pairs of switches or between Access Points (APs) and switches. Certain types of tunnels may utilize a “keep-alive” (also referred to herein as a “heartbeat”) mechanism that monitors tunnel reachability and availability. Keep-alive messages are sent and received between the Wireless Access Point and Wireless switching station, where the tunnel terminates. This ensures that the tunnel is alive and active. Keep-alive packets are sent at fixed intervals. If the tunnel end station does not receive the Keep-alive control packet in a fixed time period, it proceeds to bring down the tunnel in order to free bandwidth that would otherwise be wasted.